<code>defaultAnchor</code> - an anchor function that is used by links if no <code>anchor</code> property is defined for a link end. It can either be an object (with a <code>name</code> and optional <code>args</code>) or a function. JointJS provides a collection of <a href="#anchors">built-in anchor functions</a> in the <code>joint.anchors</code> namespace; alternatively, a <a href="#anchors.custom">custom function</a> may be provided. See the <a href="#dia.Link.geometry.anchor">link geometry anchor documentation</a> for more information.
